Synchronization of Oestrus With I.C.I. 79,939, an Analogue of Pgf2 , and Associated Changes in Plasma Progesterone, Oestradiol-17  and Lh in Heifers

Dobson, H.; Cooper, M. J.; Furr, B. J. A.

doi:10.1530/jrf.0.0420141

Cited by 38 publications

(11 citation statements)

References 8 publications

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“…Later studies with buffaloes (Pathiraja, Abeyratne, Perera & Buvanendran, 1979) emphasized the importance of correct detection of oestrus, AI technique, and adequate nutrition. Buffaloes treated during the breeding season are more fertile than those treated for suboestrus with first-service conception rates of 51-52%, and 25-44% respectively (Rao & Rao, 1979a;Singh, Dugweka, Sharma, Chauhan & Singh, 1979a (Chauhan et ai, 1982) and cows (Dobson, Cooper & Furr, 1975). In field conditions only 55-72% buffaloes and zebu displayed oestrous symptoms after PG treatment (compared to 80-90% in dairy cows); this may be due to the extra difficulties of initial luteal recognition per rectum because progesterone concentrations at the time of PG injection have been as low as 0-6 ng/ml (Chauhan et ai, 1982;Orihuela, Galina, Escobar & Riquelme, 1983).…”

Section: Fertilitymentioning

confidence: 99%

A review of female cattle reproduction with special reference to a comparison between buffaloes, cows and zebu

Dobson¹,

Kamonpatana²

1986

Reproduction

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Section: Fertilitymentioning

confidence: 99%

A review of female cattle reproduction with special reference to a comparison between buffaloes, cows and zebu

Dobson¹,

Kamonpatana²

1986

Reproduction

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“…In the present work the effects of single and multiple LH-RH injections soon after parturition were examined in suckled beef cows. In view of the prospective commercial importance of synchronization of oestrus with prostaglandin (PG) F-2a (Louis, Hafs & Morrow, 1974;Dobson, Cooper & Furr, 1975 ;Lamming, Hafs & Manns, 1975), some animals were treated with LH-RH and PGF-2a.…”

Section: Introductionmentioning

confidence: 99%

Response of cyclic and post-partum suckled cows to injections of synthetic LH-RH

Webb¹,

Ge²,

Haynes³

et al. 1977

Reproduction

122

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“…The following investigation was under¬ taken to define the temporal relationship between these hormones. Progesterone concentrations are known to remain basal (<0-5 ng/ml) throughout oestrus (Dobson, Cooper & Furr, 1975). …”

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confidence: 99%

“…The radioimmunoassays, used without modification, have been described in detail elsewhere. In the LH assay (Dobson et al, 1975) the antibody to bovine LH was raised in a horse by Dr R. B. Snook. The only significant cross-reaction was with TSH (90 %).…”

mentioning

confidence: 99%

Plasma gonadotrophins and oestradiol during oestrus in the cow

Dobson¹

1978

Reproduction

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Summary. LH values between \ m=-\ 2 and +4 h (0 h =LH peak) were higher than baseline.FSH values were also raised at this time and between + 16 and + 30h. Oestradiol values between \m=-\20 and 0 h were higher than during + 4 to + 20h.Plasma FSH levels during the bovine oestrous cycle have been measured (Akbar, Reichert, Dunn, Kaltenbach & Niswender, 1974; Deri vaux, Ectors, Hendrick & Franchimont, 1974;Schams & Schallenberger, 1976), but details of the changes in plasma oestradiol concentration and those of LH and FSH during the oestrous period have not been reported. The following investigation was under¬ taken to define the temporal relationship between these hormones. Progesterone concentrations are known to remain basal (<0-5 ng/ml) throughout oestrus (Dobson, Cooper & Furr, 1975). Materials and MethodsSix Friesian heifers, 18-36 months old, were bled (20ml) from indwelling jugular vein catheters every 2 h for 3 days, starting 1 day before oestrus. Plasma was obtained immediately by centrifugation and stored at -15°C. The radioimmunoassays, used without modification, have been described in detail elsewhere. In the LH assay (Dobson et al., 1975) the antibody to bovine LH was raised in a horse by Dr R. B. Snook. The only significant cross-reaction was with TSH (90 %). Purified bovine LH (LER 1072/2) was used as the I25I-labelled preparation. The sensitivity of the method was 0-2 ng with interand intra-assay coefficients of variation of 10-6 and 8-3% respectively. The plasma results are ex¬ pressed as ng equivalents of NIH-LH-B8/ml. For the FSH assay (Dobson, 1978) an antibody to rat FSH (S6 : obtained from NIAMDD) was used. The only significant cross-reaction was 5 % with TSH. Purified bovine FSH (LER-1695-2) was used as the 125I-labelled preparation. The sensitivity of the method was 4 ng with inter-and intra-assay coefficients of variation of 15-5 and 14-5 % respectively. The plasma results are expressed as ng equivalents of NIH-FSH-Bl/ml. The oestradiol assay (Dobson & Dean, 1974) utilized an antibody (R2B2) raised against oestradiol-6-(0-carboxymethyl) oximebovine serum albumin which had no cross-reactions of >2% with any other oestrogen known to occur in the cow. The sensitivity of the method was <10 pg with inter-and intra-assay coefficients of variation of 12-5 and 7-8 %, respectively. ResultsThe changes of LH, FSH and oestradiol concentrations in 6 heifers in relation to the time of maximum LH concentration (0 h) are shown in Text- fig. 1. The mean concentration of oestradiol between -20 and 0 h was significantly higher than during the period 4-20 h after the maximum LH concentration (Student's t test for 2 groups of unpaired data, < 0-001). The LH values between -2 and +4 h inclusive were significantly higher than baseline concentrations (P < 0-001). FSH values between-2 and +4 h were also significantly higher ( < 0-001) than those for periods of 10 h before or after this time. However, FSH values 16-30 h after the LH peak were also significanth/aajged ( < 0-001) compared to the period from 44 to +14 h.

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Synchronization of Oestrus With I.C.I. 79,939, an Analogue of Pgf2 , and Associated Changes in Plasma Progesterone, Oestradiol-17 and Lh in Heifers

Cited by 38 publications

References 8 publications

A review of female cattle reproduction with special reference to a comparison between buffaloes, cows and zebu

A review of female cattle reproduction with special reference to a comparison between buffaloes, cows and zebu

Response of cyclic and post-partum suckled cows to injections of synthetic LH-RH

Plasma gonadotrophins and oestradiol during oestrus in the cow

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